A propulsion assembly for a rotorcraft includes a mast and a proprotor hub assembly coupled to the mast and having a gimballing degree of freedom relative to the mast. The propulsion assembly includes a gimbal lock assembly positioned about the mast and including a plurality of radially outwardly extending and circumferentially distributed rollers. The gimbal lock assembly is movable between a disengaged position and an engaged position relative to the proprotor hub assembly. In the disengaged position, the gimbal lock assembly enables the gimballing degree of freedom. In the engaged position, the rollers of the gimbal lock assembly contact the proprotor hub assembly to disable the gimballing degree.